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Refrigerant Charge Calculator
Calculate the correct refrigerant charge for split air conditioning systems, including the additional charge needed for extended pipe runs beyond the manufacturer's standard length.
How to Calculate Refrigerant Charge
Split systems come pre-charged from the factory for a standard pipe length (typically 7.5 m). If your installation has longer pipe runs, you must add additional refrigerant per the manufacturer's specification — typically 20–40 g per metre.
Always check the installation manual for the exact additional charge per metre for your specific model and refrigerant. Undercharging leads to poor performance and compressor damage.
Frequently Asked Questions
How much extra refrigerant per metre of pipe?
Typically 20–40 g per metre beyond the standard included length. Check your unit's installation manual for the exact figure — it varies by model, refrigerant and pipe diameter.
What happens if I don't add enough refrigerant for long pipes?
Undercharging causes low suction pressure, high superheat, reduced cooling capacity, and potential compressor overheating due to insufficient cooling from returning refrigerant vapour.
What is the GWP shown in the results?
The CO₂ equivalent is calculated using R410A's GWP of 2,088. This shows the environmental impact if the entire charge were released. Lower-GWP refrigerants like R32 (GWP 675) have significantly less impact.
Refrigerant Charge Calculator
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